Uso de SIG na avaliação da contaminação por chumbo e cobre no Canal do Cunha e no oeste da Baía de Guanabara , Rio de Janeiro, RJ.

8 p. il.As well as other subbasins of Guanabara Bay, the Canal do Cunha's sub - basin, located in the city of Rio de Janeiro, suffered a severe environmental degradation as from the 1950s due to the accelerated urban - industrial development. Having a fluvial dynamics changed - by deforestation, dredging, occupying valleys and corrections - the channel is responsible for the flow of effluents and sediments that contribute to environmental degradation and has direct influence on water quality aggravation indices in the western portion of the Guanabara Bay. This study intends to evaluate, through GIS techniques, the spatial distribution of the levels of lead (Pb) and copper (Cu) launched by domestic sewage and industrial effluents using data provided by six points monitoring State Environmental Institute (INEA) . The representation of distributions allowed us to observe the influence of seasonality and the concentration of suspended sediment concentrations of metals. This work integrates the Canal do Cunha's characterization project, developed by the Laboratory of Environmental Impacts and Sustainability (LIMA) Nuclear Engineering Institute (IEN)

Caracterização química e radiológica do fosfogesso de Imbituba-SC e aspectos ambientais do uso na recuperação de solos agrícolas

A indústria de fertilizantes fosfatados é baseada no ácido fosfórico produzido a partir de rochas fosfáticas e gera um subproduto, o fosfogesso, cujas características químicas e físicas são semelhantes ao gesso natural (gipsita). Este material contém radionuclídeos das séries de decaimento do 238U e do 232Th, metais pesados e elementos terras raras oriundos da rocha fosfática matriz. No Brasil cerca de 6 milhões de toneladas de fosfogesso são produzidas anualmente e estocadas em pilhas. Portanto, a pesquisa visando o desenvolvimento de possíveis usos do fosfogesso torna-se cada vez mais importante, tanto do ponto de vista econômico como tecnológico e ambiental. Este material vem sendo utilizado há várias décadas como insumo agrícola no Brasil, principalmente como fonte de enxofre e cálcio e na redução do alumínio tóxico no ambiente radicular. Nesse contexto, esse trabalho teve objetivo de identificar as concentrações dos radionuclídeos, metais pesados e elementos terras raras nas pilhas de fosfogesso de Imbituba - SC, além de avaliar sua aplicação na agricultura e a absorção de radionuclídeos pelas plantas. Amostras de fosfogesso foram coletadas em dezessete pontos georeferenciados nas pilhas geradas pela indústria. Também foram coletadas amostras dos diferentes compartimentos ambientais (água, solos e plantas) no entorno das pilhas para avaliar o impacto ambiental das mesmas. As atividades de 226Ra e 228Ra foram superiores no fosfogesso quando comparados com o solo da área de referência. A concentração de atividade média do 226Ra foi 95 Bq kg-1, Esse valor está bem abaixo do limite recomendado pela Agência Ambiental Americana, para sua aplicação na agricultura. Os resultados de metais pesados no fosfogesso são menores que na área de referência e os estabelecidos pela CETESB, indicando que a presença de metais não é uma limitação do uso agrícola do fosfogesso. A normalização dos ETRs demostrou que as pilhas de fosfogesso foram geradas por rochas fosfáticas de diferentes origens. As concentrações de radionuclídeos nas águas subterrâneas estiveram abaixo das normas vigentes da Portaria No36 do Ministério da Saúde. A aplicação de doses crescentes de fosfogesso no solo não promoveu mudanças significativas nas concentrações de radionuclídeos. No estudo da disponibilidade de radionuclídeos realizado no experimento, os maiores teores de isótopos de Ra e de 210Pb estiveram associados a fração residual. As alfaces cultivadas nos solos salinos tratados com fosfogesso não apresentaram aumento significativo nas concentrações de radionuclídeos e de metais pesados. Os resultados obtidos nas análises das espécies vegetais que crescem sobre o fosfogesso demonstraram que as plantas absorveram elevadas quantidades de radionuclídeos. O fator de transferência e índices de translocação calculados mostraram que algumas espécies estudadas apresentaram um bom potencial fitorremediador.Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorThe industry of phosphate fertilizer is based on the phosphoric acid, produced from phosphate rock and generates a by-product, phosphogypsum, whose chemical and physical characteristics are similar to gypsum. This material contains radionuclides from 238U and 232Th decay chain, heavy metals and rare earth elements from phosphate rock matrix. In Brazil, nearly 6 million tons of phosphogypsum are produced annually and stockpilled. This material has been used for decades as an agricultural input in Brazil, mainly as a source of sulfur and calcium and the reduction of toxic aluminum in the root zone. In this context, this study aimed to identify the concentrations of radionuclides, heavy metals and rare earth elements in phosphogypsum stacks of Imbituba - SC, and evaluate its application in agriculture and absorption of radionuclides and heavy metals by plants. Samples of phosphogypsum were collected at seventeen points at two piles. Samples of diferent natural matrix were also collected from different environmental compartments (water, soil and plants) nearby of the phosphogypsum piles to assess their environmental impact. Also, it was carried out a greenhouse experiment with saline soils to evaluate improvements by the application of phosphogypsum. The activities of 226Ra and 228Ra were higher in phosphogypsum when compared with soil from the reference area. The mean activity concentration of 226Ra was 95 Bq.kg-1. This value is much below the limit recommended by the U.S. Environmental Agency, for its application in agriculture. The results of heavy metals in phosphogypsum are lower than in the reference area and established by CETESB, indicating that the presence of metals is not a limitation to the agricultural use of phosphogypsum. Standardisation of REE showed that phosphogypsum from Imbituba stacks were generated by phosphate rocks of different origins. The radionuclide concentrations in groundwater were below the prevailing norms of regulation 36 from the Brazilian Ministry of Health. The application of increasing rates of phosphogypsum in the soil did not cause significant changes in the concentrations of radionuclides. In the study of the availability of radionuclides carried out the experiment, the highest concentrations of isotopes of Ra and 210Pb were associated with residual fraction. Lettuce grown in saline soils treated with phosphogypsum showed no significant increase in concentrations of radionuclides and heavy metals. The results of the spontaneous plant species analysis that grew on phosphogypsum showed that the plants absorbed large amounts of radionuclides. The transfer factor and translocation indices calculated to this spontaneous vegetables indicated that some species presented a good potential for phytoremediation

Uso de SIG na Avaliação da Contaminação por Chumbo e Cobre no Canal do Cunha e no Oeste da Baía de Guanabara , Rio de Janeiro, RJ

As well as other subbasins of Guanabara Bay, the Canal do Cunha's sub-basin, located in the city of Rio de Janeiro, suffered a severe environmental degradation as from the 1950s due to the accelerated urban-industrial development. Having a fluvial dynamics changed - by deforestation, dredging, occupying valleys and corrections - the channel is responsible for the flow of effluents and sediments that contribute to environmental degradation and has direct influence on water quality aggravation indices in the western portion of the Guanabara Bay. This study intends to evaluate, through GIS techniques, the spatial distribution of the levels of lead (Pb) and copper (Cu) launched by domestic sewage and industrial effluents using data provided by six points monitoring State Environmental Institute (INEA) . The representation of distributions allowed us to observe the influence of seasonality and the concentration of suspended sediment concentrations of metals. This work integrates the Canal do Cunha's characterization project, developed by the Laboratory of Environmental Impacts and Sustainability (LIMA) Nuclear Engineering Institute (IEN).Pages: 7904-791